Stapler tool with rotary drive lockout

Abstract

A surgical stapler including an end effector having various embodiments of a lockout assembly is described. The lockout assembly can control the rotation of a drive member that extends through the end effector. A sled can be positioned along the drive member and caused to translate along the drive member upon rotation of the drive member. As such, the lockout assembly can prevent movement of the sled by controlling the ability of the drive member to rotate. The lockout assembly can assist with preventing inadvertent firing of the end effector, such as when there is no cartridge present or a spent cartridge (e.g., the cartridge does not have any staples).

What is claimed is: 
     
       1. A lockout mechanism for use with a surgical stapler, comprising:
 a rotary drive member; 
 an engagement feature disposed on the rotary drive member; and 
 a lockout assembly having
 a lockout body disposed about the rotary drive member, 
 a latch pivotally coupled to the lockout body about a pivot pin such that the latch pivots between engaged and disengaged positions, the latch and pivot pin being configured to translate linearly along the lockout body between proximal and distal positions, and 
 a latch retainer positioned between the lockout body and the engagement feature on the rotary drive member; 
 
 wherein the latch is configured to engage the latch retainer when the latch is in the proximal position and in the engaged position such that the latch retainer prevents movement of the latch to the distal position; and 
 wherein the latch is configured to engage the engagement feature on the rotary drive member when the latch is in the distal position and in the engaged position such that the latch prevents rotation of the rotary drive member. 
 
     
     
       2. The lockout mechanism of  claim 1 , wherein the latch includes a recess formed therein and having a shape complementary to the engagement feature for engaging the engagement feature to prevent rotation of the rotary drive member. 
     
     
       3. The lockout mechanism of  claim 1 , further comprising a sled coupled to the drive member such that rotation of the drive member causes linear translation of the sled along the drive member. 
     
     
       4. The lockout mechanism of  claim 3 , wherein the sled includes a latch engager that maintains the latch in the proximal position when the sled is in a proximal-most position adjacent to the lockout assembly. 
     
     
       5. The lockout mechanism of  claim 3 , wherein the sled is configured to release the lockout assembly when the sled is advanced distally to allow the lockout assembly to move to the distal position. 
     
     
       6. The lockout mechanism of  claim 1 , further comprising a biasing element that biases the latch to the distal position.